Ultralow surface recombination in p-Si passivated by catalytic-chemical vapor deposited alumina films

Low surface recombination velocity in n-Si passivated by catalytic-chemical vapor deposited alumina films

“…The experimental apparatus used in this study is shown in Fig. 1 [11]. Si substrates used for the samples were Czochralski (CZ) grown crystalline n-Si (100) wafers having a resistivity of 6 Ωcm with a mirror polished front-surface and a chemical-polished back surface.…”

“…This factor is becoming more dominant as the bulk thickness of Si wafer is being reduced to realize a reduction in cost. The surface recombination velocity in p-type Si (p-Si) has been reduced drastically due to alumina passivation films deposited by pyrolysis of aluminum triisopropoxide [3], atomic layer deposition (ALD) of TMA and H 2 O [4], plasma-assisted ALD of TMA and O 2 [5][6][7][8], plasma-enhanced chemical vapor deposition (PE-CVD) of TMA, CO 2 , and H 2 [9], spatial ALD of TMA and H 2 O [10], and Cat-CVD of TMA and O 2 [11]. On the other hand, there have been some reports on the reduction of surface recombination velocity in n-Si due to AlO x passivation films deposited by ALD of TMA and O 2 [7], and spatial ALD of TMA and H 2 O [10].…”

“…Therefore, it is necessary for passivation films in n-Si solar cells to have positive fixed charges instead. We have found newly that positive charges can also be created at the interface of AlO x films on p-Si (AlO x /p-Si) by AlO x films deposited by O 2 /TMA at flow-rate ratios below around 10 [11].…”

Formation of alumina film using alloy catalyzers in catalytic chemical vapor deposition

“…Therefore, alumina films have recently been studied to adapt them for use as surface passivation films in crystalline Si solar cells [5][6][7][8][9][10][11][12][13][14][15] and gas barrier films in organic materials [16]. Industries dealing with these products demand low cost alumina films in addition to low temperature deposition on organic materials.…”

“…Therefore, Saito et al suggested adopting iridium (Ir) catalyzer to form SiO 2 films [26]. Alumina films have been successfully formed by Cat-CVD using tri-methyl aluminum (TMA) and O 2 with iridium as the catalyzer material [15,25,[27][28][29]. However, the cost of $1000/m of Ir wire is too expensive to form low cost alumina films.…”